Officials finish buried nuclear waste cleanup at Idaho site

ARCO, Idaho (AP) — Work to dig up and remove radioactive and hazardous waste buried for decades in unlined pits at a nuclear facility that sits atop a giant aquifer in eastern Idaho has been completed, federal officials said.

The U.S. Department of Energy on Wednesday held a celebration to mark the completion of removing specifically-targeted buried waste from a 97-acre (39-hectare) landfill at its 890-square-mile (2,300-square-kilometer) site that includes the Idaho National Laboratory.

Specifically, officials targeted just under 6 acres (2.5 hectares) called the Radioactive Waste Management Complex. Officials said the work was completed 18 months ahead of schedule.

“What you’ve done here, the fact that we made a commitment — the state, the federal government, our partners, our contractors — to get things done and we got it done," said Republican Idaho Gov. Brad Little, who took part in the event. “And that’s why we’re where we are today. That’s why it brings great confidence in what takes place out here at the lab.”

The targeted radioactive waste included plutonium-contaminated filters, graphite molds, sludges containing solvents and oxidized uranium generated during nuclear weapons production work at the Rocky Flats Plant in Colorado during the Cold War.

“This project is a great example of what can be accomplished with dedicated employees, engaged management, a supportive state and involved stakeholders,” said William “Ike” White of the Energy Department.

The waste from Rocky Flats was packaged in storage drums and boxes before being sent from 1954 to 1970 to the high-desert, sagebrush steppe of eastern Idaho where it was buried in unlined pits and trenches. The area is about 50 miles (80 kilometers) west of Idaho Falls.

The landfill sits above the Lake Erie-sized Eastern Snake River Plain Aquifer that supplies farms and cities in the region. A 2020 U.S. Geological Survey report said radioactive and chemical contamination in the aquifer had decreased or remained constant in recent years. It attributed the decreases to radioactive decay, changes in waste-disposal methods, cleanup efforts and dilution from water coming into the aquifer.

The report said contamination levels at all but a handful of nearly 180 wells are below acceptable standards for drinking water as set by the U.S. Environmental Protection Agency.

Connie Flohr is manager of the Idaho Cleanup Project for the Energy Department’s Office of Environmental Management. She said the cleanup “demonstrates their ability to protect the underlying Snake River Plain Aquifer and allow for future research and development emissions at the Idaho National Laboratory site.”

The nuclear site started operating in the late 1940s under the Atomic Energy Commission, a forerunner to the Energy Department, and contamination of the aquifer began in 1952, according to the U.S. Geological Survey report.

Contamination reached the aquifer through injection wells, unlined percolation ponds, pits into which radioactive material from other states was dumped, and accidental spills mainly during the Cold War era before regulations to protect the environment were put in place.

In 1989, the area became a Superfund site when it was added to the National Priorities List for Uncontrolled Hazardous Waste Sites.

The cleanup project at the landfill site started in 2005 and is part of the Accelerated Retrieval Project. It's one of about a dozen cleanup efforts of nuclear waste finished or ongoing at the Energy Department site.

The project involving the landfill is part of a 2008 agreement between the Energy Department and state officials that required the department to dig up and remove specific types and amounts of radioactive and hazardous material.

The agency said it removed about 13,500 cubic yards (10,300 cubic meters) of material — which is the equivalent of nearly 50,000 storage drums each containing 55 gallons (208 liters). Some radioactive and hazardous remains in the Idaho landfill that will receive an earthen cover.

Most of the waste is being sent to the U.S. government’s Waste Isolation Pilot Plant in New Mexico for permanent disposal. Some waste will be sent to other off-site repositories that could be commercial or Energy Department sites.